Student1: so if you increase one you have to decrease the other to make it multiply to 250. Teacher : What did you do to the radius to get the base area? Student: Pi-r-squared... ? Teacher : What did you do to the radius to get the base area? Student1: It's, ah, pi-r-squared, so you... Teacher : Pi-r-squared. I want you to think about the x-axis. As the radius goes up by one, Teacher : think about radius squared. The radius is one, what's r-squared? Student: One Teacher : One. If the radius is 2, what's r-squared? Student: 4 Teacher : 4. So it jumped by... Student: 3. Teacher : If the radius goes up to 3, what's r-squared? Student: 9. Teacher: 9. So it jumped by... Student: 6. Teacher : 5. So as your radius goes up by 1, your height is changing Teacher : because you're squaring the radius. We haven't really had a problem like that before. Teacher : But your radius is getting squared, isn't it? Teacher : And so it isn't changing by a constant amount, it's squared. Teacher : But just to correct you, on the x-axis, is the radius going up by a constant amount? Student: Yes. Teacher : Yes. The radius goes up by a constant amount... Teacher : Yes. The radius goes up by a constant amount... Teacher : Yes. The radius goes up by a constant amount... Student1: But the base area isn't. Teacher : Right. Because of the squaring... Okay, good. Okay, number three, Teacher : Right. Because of the squaring... Okay, good.